But I doubt that somehow confirms that he is a pureblood Quincy, since I don't think that ability is only tied to purebloods(why would it be and what makes you think that?).

Apart from the bounts quincys are the only race to gather reishi from their surroundings (that i am aware of), so if ichigo showed an affinity for the talent, (an example being if his getsuga tensho gathered reishi from the air around him) it makes the likelyhood of being pureblood higher. I just want him to be related to uryu :P, they bounced off each other so well in the early story I'd love for them to be related :D.

but your point that he became a shinigami and a hollow through that reishi gathering ability would mean any quincy could do it. So why didn't they? The Getsuga Tenshou doesn't gather reishi from the air, it amplifies his swing and fires HIS rietsu. That was explained when he fought Byakuya. He's half shinigami. half quincy, but he could still be related to Uryu through his mother, but I will guarantee you now, he is not pure quincy.

I didn't say it did, i was pointing out that if he had the talent, which he really hasn't shown, the possibilty is there. There were lots of IFS in my statement :P. I know the likelyhood of him being pureblood quincy is incredibly low, but I still think it is possible. And also, if quincys were able to get shinigami powers, they wouldn't on principle. Think how much they hate hollows and believe that they should be killed not cleansed, and it makes sense that none of them would ever have tried to gain shingami powers. :S

from the beginning i thought that isshin and ryuken were brothers-in-law, for they acted so familiarly when they met earlier in the story, that would also explain the resentment ryuken displays towards isshin, for he was responsible ( at some point he said it kills him that he wasnt able to save her that day) for misakis death, which ruyken is not able to forgive, especially if isshin is/was a captainclass shinigami , his kinds natural enemy
so that theory would make ichigo and ishida cousins
furthermore its impossible for ichigo to be a pureblood, isshin being his dad confirms it, he was a shinigami, and old yama would never have let a quincy became a captain of the gotei 13

Juha Bach is the grandfather of Masaki Ishida and Ryuken Ishida. Masaki married Squad 10 Captain Isshin Shiba, who is the brother of Kaien Shiba. Isshin and Masaki change their names to Kurosaki to not be found by Juha. They have a son named Ichigo, who has a striking resemblance to his uncle Kaien. Ryuken has a son named Uryu, making Ichigo and Uryu cousins. Anyone else blown away by this!?!?

Juha Bach is the grandfather of Masaki Ishida and Ryuken Ishida. Masaki married Squad 10 Captain Isshin Shiba, who is the brother of Kaien Shiba. Isshin and Masaki change their names to Kurosaki to not be found by Juha. They have a son named Ichigo, who has a striking resemblance to his uncle Kaien. Ryuken has a son named Uryu, making Ichigo and Uryu cousins. Anyone else blown away by this!?!?

Masaki's surname was Kurosaki when Isshin first met her, its explicitly stated. Isshin did change his name from Shiba to Kurosaki which is why nobody from Soul Society ever made the connection with Ichigo. I'm guessing its more likely that Ryuken had a thing for Masaki and she chose Isshin over him rather than Masaki and Ryuken being related. While it makes sense for Isshin to take Masaki's name in order to hide his identity, there would be no reason for Ryuken to randomly change his last name from Kurosaki to Ishida along with his father as well, unless they are some sort of matriarchal society, but I've seen no evidence for that.

wait a min. did i miss something??!!!!! im SO CONFUSED!!!! WHAT!!!!!!!!!! Can some one tell me where to find this info. Actually i haven't really read the manga So thats probably the problem... Can you tell me where i can continue reading if i finished the anime what Chapter or what ever.... ( I don't usually read manga but bleach is that awesome)

wait a min. did i miss something??!!!!! im SO CONFUSED!!!! WHAT!!!!!!!!!! Can some one tell me where to find this info. Actually i haven't really read the manga So thats probably the problem... Can you tell me where i can continue reading if i finished the anime what Chapter or what ever.... ( I don't usually read manga but bleach is that awesome)

You'll probably have to check it out on a manga site like Mangareader, as I don't think the current official manga translations have caught up to the current arc. Note that the OP is proposing some wild speculative theory that isn't actually material in the manga. Not that its not fun to speculate of course. The only things that are definitely true so far are:

1: Ichigo's mother Kurosaki Masaki was indeed a Quincy
2: Kurosaki Isshin was originally Shiba Isshin until he took Masaki's last name, likely in order to conceal his identity. Which worked because no one made the connection to Ichigo since Isshin whereabouts were unknown prior to the confrontation with Aizen.
3: Isshin was the captain of squad 10, immediately prior to Hitsugaya, who happened to be his third seat with Matsumoto being his vice-captain.(Honestly I'm surprised this wasn't speculated more in the past, everyone speculated that he was a captain but very few speculated that he was from squad 10 even though we knew that the 10th squads captain died immediately prior to turn back the pendulum and Matsumoto and Hitsugaya weren't even Shinigami at that point, so someone else had to be squad 10's captain for at least some portion of the last 100 years.)